audiodharma CABLE COOKER Pro Version 2.5
I don't know about other reviewers, but doing audio cable reviews has always ranked somewhere above sucking face with a grizzly bear on my list of things to avoid. When do you know the cables are sounding their best? It's pretty clear (unless you are one of those self-appointed iconoclasts proclaiming "break-in is a myth") that most wires with no playing time tend to sound edgy, dynamically and spatially constricted, and relatively monochromatic. But how much break-in does a loudspeaker cable or interconnect or power cable need? Can you overdo it? Does break-in last? Do you really have to break them in all over again if you move them? Faced with these and other similarly maddening considerations, I have generally preferred to minimize cable swapping and avoid writing cable reviews.
But now that may change. The first rays of a new cable-evaluating dawn are piercing my personal darkness. The audiodharma CABLE COOKER, developed and marketed by the enterprising Alan Kafton at Audio Excellence Az, is designed to maximize the sound quality of power, loudspeaker and interconnect (including A/V and phono) cabling by going far beyond the "normal" break-in that comes from using the cables in a system.
Kafton asserts, for example, that giving an interconnect a single day's burn-in on the CABLE COOKER equals a week or more of continuous system operation. He says that any kind of cable breaks in more thoroughly on a Cooker because of exposure to extreme signal levels and a special waveform that does not occur in normal system operation. The cooker's burn-in circuit supplies >1 watt for interconnects and 22 watts for speaker and power cabling, while generating a dynamic extended-frequency sweep.
The CABLE COOKER is a highly versatile device. Its universal switching power supply is usable worldwide, with all line voltages from 90 VAC to 260 VAC, and AC frequencies from 47Hz to 63Hz.
The circuitry in the standard version 2.5 Cooker is identical to that of that of the Pro version reviewed here. The Pro version is built for heavy-duty usage, and therefore features upgraded heavier-duty all-metal speaker binding posts; a double-ball-bearing interior cooling fan; and a bridging switch that enables simultaneous break-in of interconnects, speaker cabling and power cabling. This bridging switch is a $30 upgrade option on the standard Cooker.
Break-In: A Conceptual Overview
Cable break-in occurs as current flows through the conductors of wiring components. Dielectric stress from voltage differences between conductors also contributes. It takes many hours of in-system use for wiring components to break in, primarily because audio/video signals from normal program material are so low-level.
Consider an interconnect from pre-amplifier to power amplifier. The maximum signal level for full power output of the average power amplifier is 2 volts peak, and the average signal is much less. Typical input impedance of a power amplifier is 10 kohms at the low end for consumer gear; 47 to 100 kohms is typical for a solid-state amplifier, while several hundred kohms impedance is not unusual for a tube power amplifier.
Taking the best-case values from the above, the maximum current seen is 2 Volts/10k ohms, or 200 micro-amperes. This would not be continuous current, because the voltage value is peak, not rms. One can calculate a "use value" from the above equation multiplied by the total time this current flows. Let's call that the Current Time Value (CTV).
Playing an interconnect cable in an audio system for one week (168 hours) of continuous use would expose it to the following CTV: 168 hours x 0.0002 amperes = CTV of 0.0336.
The CABLE COOKER produces signal levels far higher than those seen in normal audio/video system use. The Cooker's sweeping square wave oscillator drives a high-efficiency "H" bridge MOSFET switching circuit. The output signal is a square wave from below 100Hz to above 16 kHz, plus harmonics. Output voltage is 12 volts rms. The measured current flowing through the interconnect is 120 milli-amperes.
Installing an interconnect on the Cooker for one week results in a CTV of 168 hours x 0.12 Amperes = CTV of 20.16. This is a value 600 times greater than under the most ideal audio system conditions. The "stress" on the dielectric is also much higher due to the higher output voltage. Results with the Cooker are typically audible after less than a day.
The same signal also feeds the speaker cable binding posts. The load at the speaker cable inputs draws a continuous 1.88 amperes of current through the wire. With a potential of 12 volts, this is equivalent to a continuous signal level in excess of 22 watts rms. This continuous signal level played through loudspeakers in a home environment would be unbearably loud. Put simply, there is no way for conventional in-system playback burn-in to approach the intensity and efficiency of the Cooker.
Hooking For Cooking
RCA-terminated interconnects may be daisy-chained using barrel connectors (a few pair are supplied with every Cooker). XLR-terminated interconnects simply snap together to run in series and directionally. Speaker cable adapters ($50 per pair), each with two sets of five-way binding posts, allow simultaneous break-in of multiple sets of loudspeaker cables.
Each Cooker comes with a pair of reverse-male/female 3-blade/IEC adaptors to connect a power cable for break-in. Banana plugs at the opposite end of each adapter insert into designated speaker binding posts. Power cable break-in occurs on the same high-level circuit used to break in speaker cables. Additional "extension adaptors" ($10) allow multiple power cables to be daisy-chained.
Note: Alan Kafton will henceforth be offering custom Schuko and UK13-style power cable break-in adapters, needed by some overseas customers. Contact him for price and availability.
A special DIN-to-RCA phono adaptor ($50) allows break-In of tone arm wires and phono cables. It utilizes a Cardas 5-pin DIN connector and Cardas RCA plug, a five-foot cable suited for low-level signals, and a Velcro band that wraps around the adaptor and arm to keep everything immobile and safe during break-in.
This capability strikes me as especially useful; given the incredibly low voltages generated by cartridges (especially low output moving coils). Tone arm wire and phono cables are virtually never truly broken in and conditioned by playback. The Cooker's multiplex output signal is about 2,000 times stronger than that of the average MC cartridge.
There is no practical limit to the number of interconnects, speaker cables and power cables you can burn in at once. There is no degradation or loss of signal strength or integrity, no matter how many cables are connected to the Cooker.
How Much Break-In Time?
Alan Kafton asserts that cable break-in is long-term but not permanent. He suggests that cabling (especially in the dielectric materials) benefits from a periodic "recharge" of 12 to 24 hours every few months. He says many Cooker owners do this chore every 3 or 4 months. This of course makes the Cooker a better long-term value.
Cooking And Re-Cooking Chez Donnelly
I have been using some of the cables in my primary system for years, and when the Cooker arrived there was not a single cable in that system with less than several hundred hours of in-system use. I "re-cooked" every wire in the system, in three stages: first power cords, then speaker cables, and finally interconnects. The improvements after every stage were quite substantial, and the cumulative effect was so far beyond expectation that I began to wonder if I was hallucinating. The effect was similar to what happened about a year ago when I pulled all of the cables out of the system and had them cryogenically treated. But the results from re-conditioning these supposedly already well-seasoned cables on the Cooker were even more dramatic.
As a final test, just before writing this review I again re-cooked all of my system cabling, this time all at once, for 24 hours. The degree of improvement this time was not so radical, but was nonetheless easy to hear, and definitely worth the trouble.
Who Needs It?
What about reviewers? Frankly, I can't imagine attempting to review audio cables without first conditioning them with the Cable Cooker or an equivalent-acting device. Any cable review based only on in-system break-in is in my opinion not worth reading -- or writing. And for that matter, component reviews done with insufficiently burned in cables cannot possibly evaluate those components at their full potential.
With respect to the standard Enjoy the Music.com component rating chart, I will say simply that every parameter listed there is materially improved by burning in system cables with the audiodharma Cable Cooker.
Audio Excellence Az